Unsolicited book review: Spillover, by David Quammen

This is a damn scary book. Quammen is perhaps our best science writer, and his subjects in the past have ranged widely, from island biogeography to large predators to whatever he fancies in his excellent collections of essays. And this time he’s picked something topical, timely and thoroughly terrifying. It’s zoonosis—the phenomenon of diseases that are directly transferable from animals to humans. You know, AIDS, Marberg, Ebola, SARS, and a bunch you’ve probably never heard of. Oh, and the massive influenza following the first World War that killed more people than the war did. These are all zoonosis, and a spillover has occurred with each one—that moment when the virus (which it usually is) jumps from one species to another. And Quammen has written a page-turner about them. To say that it’s wonderfully written almost seems out of place, but it is.

We all think we know what these diseases are capable of, but we’re wrong. It’s much worse. Not that Quammen is out to scare us—rather, he wants to put all of it in some perspective, and lay a few popular myths to rest. But still, you finish the book feeling that we’ve been damn lucky, and like much of the community of scientists and health professionals profiled in the book, we’re nervous. But we now know what can happen, why it will be difficult to stop, and what the potential damage might be—I say potential because only with AIDS have we so far seen a true global epidemic. With the rest of it, we’ve gotten off easy, so to speak.

Quammen has integrated a number of detective stories here. First, why are there suddenly a whole new raft of terrifying diseases? Second, where do they come from? Third, what can we do about them? The answers here are not particularly comforting. They relate to a wide range of factors—population growth, population expansion into areas inhabited by primates and bats, the phenomenal mobility of human beings in the late 20th and early 21st century, the critical population size required for an epidemic to take root, and the fact that most of these diseases are viruses, and therefore can’t be treated by antibiotics. This is quite a list, and if it seems that they have all converged in the past two or three decades, that’s because they have. Quammen seems to cover it all.

There are several diseases that Quammen investigates in considerable detail—Marburg, Ebola, Hendra, SARS, and, of course, AIDS, which occupies the largest section of the book. AIDS has been by far the largest killer, and is still not under complete control, but appears to have reached some sort of stasis. But they’re all lurking out there. And then, of course, there is the NBO—the Next Big One. Which everyone in the field appears to be resigned to, kind of like seismologists. This is not comforting, but it’s necessary knowledge. Quammen even covers Lyme disease, and it turns out that nearly everything I thought I knew about it was wrong. For one thing, it has almost nothing to do with deer.

And Quammen doesn’t skimp on the science, I’m glad to say. We learn a lot about viruses and how and why they can be so dangerous—for one thing, there are different kinds of viruses. And we learn even more about how difficult it is to track these things down. There’s an art of assessment getting profiled here—the people who have to make decisions about these things are almost always operating with incomplete knowledge—what is the reservoir (the incubator for the disease that seems itself to be resistant)? How can we determine what it is (hint—it’s probably a primate or a bat)? This turns out to be insanely complicated, and much of the book follows Quammen’s investigation of this search for the reservoir of several recent zoonotic outbreaks. This is both chilling and thrilling, and Quammen is an informed guide.

Quammen devotes a substantial amount of the book—pretty much the last 100 pages or so—to theorizing how AIDS got started—over a century ago. Yes, that’s how long AIDS has been around for. So far as we can tell, AIDS got it start in humans in 1908 as the result of what Quammen describes as “a single bloody encounter between a human and a chimpanzee” in Southeastern Cameroon. Bad for both, obviously. In fact, another thing we learn is how some of the primate populations in Africa are being decimated as well. So what made AIDS take off when it did, after remaining relatively dormant for decades? Quammen devotes considerable discussion to the various theories about this—it’s a complicated story, and Quammen does it justice.

The heroes are many—generally healthcare professionals, many no longer with us because of exposure to something; scientists roaming the rivers of Africa, or wherever some new strain of something really communicable and often of unknown origin has shown up; Public Health officials, whose decision-making is often bedeviled by vastly incomplete and rapidly evolving knowledge. This book is, among other things, humbling for those of us not involved in these various, and often noble, pursuits.

Quammen ends on a hopeful note. We’ve managed to avoid several potential disasters, and with each one, we get better at spotting these spillover outbreaks. But I can’t decide if he’s just telling us that to make us feel better, or if he really believes it. Because there’s no question that there’s the potential for massive global disaster here, and that our penetration into more and more previously sparsely inhabited regions just worsens the odds.

Post navigation

i remember reading a cdc quote once where the scientist was talking about how lucky we got with aids because it’s relatively hard to transmit. and the guy started talking about the perfect virus–the virulence of the spanish influenza, the lethality of aids, and he had some other stuff in there as well, but the point was we’ve never seen the perfect virus. i also remember reading about some simulations they did (DOD, of course,) saying if a new virus broke out how long would we have to quarantine it, and the answer was something like six hours. after that, its spread

Thanks. Otherwise, you know, six hours sounds about right in some instances. It depends. For the ones that seem to emanate from or pass through China and Hong Kong–think SARS here– with the astonishing mobility that has come along the past couple of decades, it might not even be that.